Application WO-A-2009022929 describes an automatic golf ball collection system that can function autonomously or remotely controlled.
It includes an artificial vision system to detect the balls to be collected, and a processing system which processes the images acquired by the artificial vision system, and which individually controls motors which move a collection vehicle, defining a path to be followed according to the detections found in the images. Several operational modalities are proposed with reference to the path to be followed by the collection vehicle e.g. it has to pass along some designated control points or control locations which are previously defined by a positioning system (for example GPS) of the own collection systems. The system provides the installation of a great variety of sensors which allow it to avoid all kind of obstacles and irregularities of the field (since it is intended for outdoor use: in particular for a golf course), as well as to return to the base station if weather conditions are adverse.
DE-A-19711298A discloses a method and a device for the detection and automatic collection of objects, such as tennis balls, with a computing system including an opto-electric detection system comprising one camera, a laser scanner or a sonar sensor that depending on the application even can be combined. The device analyzes the surroundings, it detects the elements to be collected, and it determines the collection trajectory, along which the device can redirect its path to avoid obstacles or to choose an alternative itinerary.
In US-A-20080189004 a vehicle for ball collection in a golf course is disclosed, which follows either one balls collection trajectory or another one based on the information relative to the balls distribution on the field. The information can be acquired by means of a visual sensor located on the vehicle itself or on a remote unit. Its specification indicates that collection of other types of balls can be a performed, such as those for tennis.
In EP-B 0372249 a device to collect tennis balls in an automatic way is proposed, as well as to smooth the playing surface by means of a brush.
In the cited applications possible interaction of the ball collection apparatus or device with the player is unsolved or little developed, whereby the possibility for the device to deliver the game balls or balls to the player and generally the response time is deficient to use the application in a game dynamic without imposing restraints or excessive changes.
The purpose of this invention solves such deficiencies.
Explanation of the Invention
The invention relates to an automatic collection method of spherical game elements, such as a ball and in particular a tennis ball, of the type providing to perform, in an automatic way, the following steps generally known by the cited prior art:
a) acquiring a sequence of images of at least one surveillance area of a game surface, generally comprising any part of the game surface;
b) analyzing said images to detect the presence of at least one spherical game element in said surveillance area; and
c) moving a collection apparatus of spherical game elements to the location of said detected spherical game element, which is at least one, and proceed to collect it.
According to the procedure of this invention said step b) includes the detection of at least said spherical game element from the moment in which it is launched by a stroke or hit by the player by means of a stick, paddle or racket, or even before (on the basis of detecting a position and/or movement of the paddle or racket of the player prior to the impact with the ball), during a motion of deceleration, and/or along its path following its launch (both in acceleration and deceleration) so as to determine, as soon as possible, that its impact or fall will take place beyond the determined play area, or of said game surface. Furthermore according to the principles of this invention said step c) begins when, as a result of the analysis of said step b), one confirms that the spherical game element is going to remain inside and/or to exit from said determined game area.
In this way the collector apparatus of spherical elements will start and go towards the collection area brief instants after the launch of the spherical element, and the collection and the subsequent delivery to the player will be carried out in the least possible time.
According to the invention the collection apparatus, which is at least one, also performs the delivery of the spherical element to the player, on request of said player, or in an automatic way (prefixed command by a user), from a collection point, approaching the player up to a determined distance or via an intermediate delivery mechanism selected between a ball launcher machine, a ball storage deposit with auxiliary launcher device and a ball dispenser at a determined height with manual collection by the player, to whom said collection apparatus delivers the ball, and said apparatus returning following said delivery to a given position or starting another collection.
It is also a characteristic of the proposed method that said player request can be performed by means of several communication ways, vocal, gestural, by a wireless device, or by combination of these ones. This particularity allows the method to be applicable to players with different disabilities, elderly people or who require different arrangements, in some way specific for the practice of the game that the method allows to take place.
According to the proposed method the collection apparatus, which is at least one is situated at a game area, close to a game area, or after the spherical element delivery it returns to a game area in which by means of statistical calculations of a game or of a series of games previously played by one or more players, it has been established that a greater number of spherical game elements will impact or fall. This condition leads to greater efficiency of the movement of the collection apparatus, because after the delivery of the ball it will go unless otherwise instructed towards an area more likely for spherical elements to impact or fall, facilitating the collection.
In a preferred embodiment of the invention it provides at least two collection apparatuses, which operate in a complementary manner performing the collection or delivery of the spherical elements and moving in a coordinated and/or synchronous way in order to optimize the delivery time to the player of a spherical element following its collection, said two apparatuses sharing out the collection and/or delivery tasks or moving a first one of said apparatuses towards a predetermined area chosen between one of the cited areas of impact or fall of spherical game elements (which can have been calculated by means of trajectories detection, or statistically provided), while a second apparatus performs a collection or delivery.
Relatively to the method for the automatic collection and delivery of spherical game elements, such as a tennis ball of the present invention, in said step b) it has been provided to analyze the images of any zone of the game surface so as to detect any other objects or people which are present in said area of surveillance, both with reference to their position as well as with reference to the fact that they are still or they are moving, allowing to acquire their movements. Furthermore, this step b) comprises the calculation of the movement trajectory of the ball 11, referred to in step c) as a function of the detected objects and/or of the position of the player with respect to the spherical element at the time of its stroke or hit or prior to it.
By means of the cited strategy it is possible to immediately inform the collection apparatus 14, about the zone in which the ball 11 is going to fall or it is even possible to indicate to said apparatus 14 to perform movements to avoid or to try to avoid a ball 11, in order to maintains a safety distance in case of persons 13, and so that, in any case, it arrives as fast as possible at the location of the spherical game element or ball 11 to be collected.
According to an additional characteristic it has also been provided that in said step b), one proceeds to detect the presence of a plurality of spherical game elements to be collected in said surveillance area, and an optimal itinerary is calculated, in time and distance, for its collection in a shared way by the collection apparatuses which are at least two and which are initially located (when the game begins) at a lateral or end zone of a tennis court, finally performing at the end said step c) to collect all the spherical game elements.
The collection apparatus of the invention is provided to operate in such a way that it delivers the ball by sliding on the game surface, launching it to perform at least a bounce before reaching the player, or throwing it at a determined height depending on the particular characteristics of the player in order to enable the game to be adapted to people with disabilities or physical deficiencies, calculating for this purpose the distance from the delivery point to the player and the receiving conditions. It has also been provided that the collection apparatus approaches a point close to the player so that he can receive the ball practically in the hand.
As indicated the invention also refers to a system for the automatic collection of spherical game elements such as a ball and in particular a tennis ball, of the type that includes:                some images acquisition means provided to acquire image sequences of at least one area of surveillance;        a collection apparatus of spherical game elements provided to move and collect spherical game elements, in an automatic way; and        some control means, in connection with said acquisition and image processing means in communication with said spherical game element collection apparatus, wherein said control means are provided to process at least part of said images to detect the presence of at least one spherical game element in said surveillance area, and to send a control command to said spherical game element collection apparatus so that it moves to the location of said detected spherical game element, which is at least one, and it proceeds to collect it, all according to a structure in part already implemented in various of the cited prior art.        
The system of the present invention in addition includes at least two collection apparatuses provided to operate in a complementary and/or synchronized way so as to perform said collection tasks, associated to said control means, and each of said apparatuses is provided to be able to perform a delivery of the collected spherical element to the player, in response to a request from him, said at least two apparatuses operating in a complementary and/or synchronized way during said delivery tasks.
Such apparatuses have small dimensions facilitating the transportation of the system including optional cameras for the surveillance of the playing surface, although already installed cameras on the playing course can be used.
Finally the invention relates to the own characteristics of one of the two used collection apparatuses, advantageously, in the cited system, and which integrate means to interact with a player to perform a controlled delivery to a player of the collected spherical object, or go and collect a determined spherical element, in response to an order given by the same by means of a vocal order, gestural order, electronic device or by means of a combination of these means.
Other characteristics and particularities of the present invention will be apparent with greater clarity in the following detailed explanation of an exemplary embodiment, applied to a tennis court, which is provided as a non-limiting example.